// 箭头函数看起来很简洁
let arr = [1, 2, 3]
let arrow = arr.map(item => item += 1)
console.log(arrow);


// 箭头函数不会创建[[Construct]]方法
class Normal { }
  Normal.prototype.name = "lilei"
const stu = new Normal
console.log(stu.name);

const Arrow = () => { }
// const aw = new Arrow() // TypeError: Arrow is not a constructor




// 箭头函数没有arguments属性
function Demo_Normal() {
  return arguments.length
}
console.log(Demo_Normal(1, 2, 3));
const Demo = () => { return arguments.length } // wtf 5?
console.log(Demo(1, 2, 3));




// 箭头函数的this指向
// 箭头函数不能通过call apply bind来改变this的值
